Nylon and composite baseplates are the most popular choice for good reason—they offer an excellent balance of flex, vibration dampening, and durability that works for the vast majority of riders. The glass-filled nylon construction absorbs chatter and bumps better than metal, giving you a smoother ride, especially on rough or icy terrain. They also have a bit more torsional flex, which makes them more forgiving when you're learning or landing tricks.
You'd only want to step up to aluminum or carbon if you're an aggressive freerider or racer who prioritizes instant response over comfort. For all-mountain cruising, park riding, or anything short of charging big lines at high speed, composite baseplates deliver the performance you need. They're also incredibly durable and often outlast metal baseplates in harsh, cold conditions. Don't assume pricier materials mean better—composite is the right call for most snowboarders.